Hi John I used a power cable plugged into my fused supply and removed the fuse and using crocodile clips on my AVO 7 multimeter so it is in series with my power supply, the red lead goes to the plus

The gate bias for IRF510 60-mA is a good point to work in class AB to balance amplification linearity and power consumption. From my observation, if it is too small, the RF output will

Question for Adam: How does the IRF510's gate bias current affect transmit power? Thank you, John AA7US

That's a good point to remember about the CS series transceivers having higher RX current due to the operation of the sandwich VFO. Keep in mind the sandwich VFO assembly instructions mention you can

Bob, If I remeber correctly from my build of knq7a, the counterclockwise amperage is approx 480mA (540mA - 60mA). The pot gets turned clockwise to increase the bias approx 60mA up to 540mA. I do

Don't forget to make sure the Final FET is insulated from the case.

Thanks John, Your explanation is excellent and very clear. Will help me a lot when I get to that point. Regards, John Vo1jcc

Thanks, John. In TX mode, even there is no voice to drive the RF output, the current consumption is still much bigger than RX mode because of the TX chain bias current and relay coil current

Hey gang, I just finished assembling a CS-40 yesterday and went through the TX alignment. After reading about all the destroyed IRF510's, I was a bit nervous when setting the bias current. Here's how

Sorry Bob, That's not the question I was asking. Where on the PCB should I touch with the positive probe to read the bias current. Many thanks, John vo1jcc.

To John Just re-read your question posed about where you check the current amps. " As a point of interest where do you check the current amps. From which point to ground? " When you check voltage you

Hi John I use an ammeter in the supply line in series to read the current. The receiver draws 44mA and if the Bias current was 60mA then the total current draw would be 100mA. It actually might

Hi Bob, Should be soon checking this myself. As a point of interest where do you check the current amps. From which point to ground? Sorry can't help you with your problem. John, vo1jcc.

Hi Working on 40m Txcr with Ver 2.2 board. A little confused about the Bias Current setting. The procedure says with the bias setting pot turned fully anti-clockwise start turning it clockwise

Larry's way is okay but not the best. Please follow the way in manual for good performance. 于 2017-7-18 7:53, John Cronhelm johncronhelm@... [CHINA_QRP] 写道:

The winding of the 3 smaller toroids that you describe is very different from the way it is described in the manual. Not sure why the difference. John, vo1jcc.

OK, I am finally ready to announce the Dual Band modification to the KN-Q7A or CS-series radio using the Sandwich VFO. The modification is easy. I can provide the Sandwich code modification based on

OK, I am finally ready to announce the Dual Band modification to the KN-Q7A or CS-series radio using the Sandwich VFO. The modification is easy. I can provide the Sandwich code modification based on

The difference (main) between Rev C and Rev D is the addition of a speaker mike capability. Thus, an additional pin is added to the printed circuit board. The speaker/mike will work with either Rev

Bob, Please download the full manual package including schematic from: manual for PCB V2.2, including schematics and partlist for 80/75/40/20m The 5 pin connector has one additional pin for speaker